1,1,2,2,3,3,4,4-Octafluorobutane compositions

ABSTRACT

Compositions include compositions of 1,1,2,2,3,3,4,4-octafluorobutane and a hydrocarbon having from 3 to 7 carbon atoms. Specific examples include 1,1,2,2,3,3,4,4-octafluorobutane and butane, cyclopropane, isobutane, propane, cyclopentane, 2,2-dimethylbutane, n-pentane, 2-methylbutane, cyclohexane, 2,3-dimethylpentane, 3-ethylpentane, heptane, hexane or methylcyclopentane. Also included in this invention are compositions of 1,1,2,2,3,3,4,4-octafluorobutane and ethyl formate, propylene oxide, bis(pentafluoroethyl)sulfide, dimethoxyethane or tetrahydrofuran. These compositions, which may be azeotropic or azeotrope-like, may be used as refrigerants, cleaning agents, expansion agents for polyolefins and polyurethanes, aerosol propellants, refrigerants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents or displacement drying agents.

This is a continuation, of application Ser. No. 08/486,427 filed Jun. 7,1995, now abandoned, which is a divisional application of Ser. No.08/314,836 filed Sep. 29, 1994, now U.S. Pat. No. 5,562,853 which issuedOct. 8, 1996.

FIELD OF THE INVENTION

This invention relates to refrigerant compositions that include1,1,2,2,3,3,4,4-octafluorobutane. These compositions are useful asrefrigerants, cleaning agents, expansion agents for polyolefins andpolyurethanes, aerosol propellants, refrigerants, heat transfer media,gaseous dielectrics, fire extinguishing agents, power cycle workingfluids, polymerization media, particulate removal fluids, carrierfluids, buffing abrasive agents, and displacement drying agents.

BACKGROUND OF THE INVENTION

Fluorinated hydrocarbons have many uses, one of which is as arefrigerant. Such refrigerants include trichlorofluoromethane (CFC-11)and chlorodifluoromethane (HCFC-22).

In recent years it has been pointed out that certain kinds offluorinated hydrocarbon refrigerants released into the atmosphere mayadversely affect the stratospheric ozone layer. Although thisproposition has not yet been completely established, there is a movementtoward the control of the use and the production of certainchlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) under aninternational agreement.

Accordingly, there is a demand for the development of refrigerants thathave a lower ozone depletion potential than existing refrigerants whilestill achieving an acceptable performance in refrigeration applications.Hydrofluorocarbons (HFCs) have been suggested as replacements for CFCsand HCFCs since HFCs have no chlorine and therefore have zero ozonedepletion potential.

In refrigeration applications, a refrigerant is often lost duringoperation through leaks in shaft seals, hose connections, solderedjoints and broken lines. In addition, the refrigerant may be released tothe atmosphere during maintenance procedures on refrigeration equipment.If the refrigerant is not a pure component or an azeotropic orazeotrope-like composition, the refrigerant composition may change whenleaked or discharged to the atmosphere from the refrigeration equipment,which may cause the refrigerant to become flammable or to have poorrefrigeration performance.

Accordingly, it is desirable to use as a refrigerant a singlefluorinated hydrocarbon or an azeotropic or azeotrope-like compositionthat includes a fluorinated hydrocarbon.

Fluorinated hydrocarbons may also be used as a cleaning agent or solventto clean, for example, electronic circuit boards. It is desirable thatthe cleaning agents be azeotropic or azeotrope-like because in vapordegreasing operations the cleaning agent is generally redistilled andreused for final rinse cleaning.

Azeotropic or azeotrope-like compositions that include a fluorinatedhydrocarbon are also useful as blowing agents in the manufacture ofclosed-cell polyurethane, phenolic and thermoplastic foams, aspropellants in aerosol, as heat transfer media, gaseous dielectrics,fire extinguishing agents, power cycle working fluids such as for heatpumps, inert media for polymerization reactions, fluids for removingparticulates from metal surfaces, as carrier fluids that may be used,for example, to place a fine film of lubricant on metal parts, asbuffing abrasive agents to remove buffing abrasive compounds frompolished surfaces such as metal, as displacement drying agents forremoving water, such as from jewelry or metal parts, as resistdevelopers in conventional circuit manufacturing techniques includingchlorine-type developing agents, or as strippers for photoresists whenused with, for example, a chlorohydrocarbon such as1,1,1-trichloroethane or trichloroethylene.

SUMMARY OF THE INVENTION

The present invention relates to compositions of1,1,2,2,3,3,4,4-octafluorobutane (HFC-338pcc) and a hydrocarbon havingfrom 3 to 7 carbon atoms. Specific examples include HFC-338pcc andbutane, cyclopropane, isobutane, propane, cyclopentane,2,2-dimethylbutane, n-pentane, 2-methylbutane, cyclohexane,2,3-dimethylpentane, 3-ethylpentane, heptane, hexane ormethylcyclopentane. Also included in this invention are compositions ofHFC-338pcc and ethyl formate, propylene oxide,bis(pentafluoroethyl)sulfide (3110Sβγ), dimethoxyethane ortetrahydrofuran (THF). These compositions are also useful as cleaningagents, expansion agents for polyolefins and polyurethanes, aerosolpropellants, heat transfer media, gaseous dielectrics, fireextinguishing agents, power cycle working fluids, polymerization media,particulate removal fluids, carrier fluids, buffing abrasive agents, anddisplacement drying agents. Further, the invention relates to thediscovery of binary azeotropic or azeotrope-like compositions comprisingeffective amounts of HFC-338pcc and a hydrocarbon having from 3 to 7carbon atoms. Specific examples include HFC-338pcc and butane,cyclopropane, isobutane, propane, cyclopentane, 2,2-dimethylbutane,n-pentane, 2-methylbutane, cyclohexane, 2,3-dimethylpentane,3-ethylpentane, heptane, hexane or methylcyclopentane. Also included inthis invention are compositions of HFC-338pcc and ethyl formate,propylene oxide, 3110Sβγ, dimethoxyethane or THF to form an azeotropicor azeotrope-like composition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and butane at 25° C.;

FIG. 2 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and cyclopropane at 25° C.;

FIG. 3 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and isobutane at 25° C.;

FIG. 4 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and propane at 25° C.;

FIG. 5 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and cyclopentane at 25° C.;

FIG. 6 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and 2,2-dimethylbutane at 25° C.;

FIG. 7 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and n-pentane at 18.33° C.;

FIG. 8 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and 2-methylbutane at 25° C.;

FIG. 9 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and ethylformate at 25° C.;

FIG. 10 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and propylene oxide at 25° C.;

FIG. 11 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and 3110Sβγ at 25° C.;

FIG. 12 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and cyclohexane at 25° C.;

FIG. 13 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and dimethoxyethane at 25° C.;

FIG. 14 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and 2,3-dimethylpentane at 25° C.;

FIG. 15 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and 3-ethylpentane at 25° C.;

FIG. 16 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and heptane at 25° C.;

FIG. 17 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and hexane at 25° C.;

FIG. 18 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and methylcyclopentane at 25° C.; and

FIG. 19 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-338pcc and THF at 25° C.

DETAILED DESCRIPTION

The present invention relates to compositions of HFC-338pcc and ahydrocarbon having from 3 to 7 carbon atoms. Specific examples includeHFC-338pcc and butane, cyclopropane, isobutane, propane, cyclopentane,2,2-dimethylbutane, n-pentane, 2-methylbutane, cyclohexane,2,3-dimethylpentane, 3-ethylpentane, heptane, hexane ormethylcyclopentane. Also included in this invention are compositions ofHFC-338pcc and ethyl formate, propylene oxide, 3110Sβγ, dimethoxyethaneor THF.

1-99 wt. % of each of the components of the compositions can be used asrefrigerants. Further, the present invention also relates to thediscovery of azeotropic or azeotrope-like compositions of effectiveamounts of each of the above mixtures to form an azeotropic orazeotrope-like composition.

This invention includes the following components:1,1,2,2,3,3,4,4-octafluorobutane, CF₂ HCF₂ CF₂ CF₂ H, HFC-338pcc,boiling point=44° C.; butane, CH₃ (CH₂)₂ CH₃, boiling point=0° C.;cyclopropane, --CH₂ CH₂ CH₂ --, boiling point=-33° C.; isobutane, CH₃CH(CH₃)CH₃, boiling point=-12° C.; propane, CH₃ CH₂ CH₃, boilingpoint=-42° C.; cyclopentane, --CH₂ CH₂ CH₂ CH₂ CH₂ --, boiling point=49°C.; 2,2-dimethylbutane, CH₃ CH₂ C(CH₃)₂ CH₃, boiling point=50° C.;n-pentane, CH₃ (CH₂)₃ CH₃, boiling point=36° C.; 2-methylbutane, CH₃ CH₂CH(CH₃)CH₃, boiling point=28° C.; ethyl formate, HCOOC₂ H₅, boilingpoint=54° C.; propylene oxide, C₃ H₆ O, boiling point=34° C.;bis(pentafluoroethyl)sulfide, 3110Sβγ, C₂ F₅ SC₂ F₅, boiling point=37°C.; cyclohexane, --CH₃ CH₂ CH₂ CH₂ CH₃ --, boiling point=80.7° C.;1,2-dimethoxyethane, CH₃ OCH₂ CH₂ OCH₃, boiling point=83° C.;2,3-dimethylpentane, CH₃ CH(CH₃)CH(CH₃)CH₂ CH₃, boiling point=90° C.;3-ethylpentane, CH₃ CH₂ CH(CH₂ CH₃)CH₂ CH₃, boiling point=93° C.;heptane, CH₃ (CH₂)₅ CH₃, boiling point=98.4° C.; hexane, CH₃ (CH₂)₄ CH₃,boiling point=69° C.; methylcyclopentane, C₆ H₁₂, boiling point=72° C.;and tetrahydrofuran, C₄ H₈ O, boiling point=66° C.

HFC-338pcc may be made by refluxing the potassium salt ofperfluoroadipic acid in ethylene glycol as reported by Hudlicky, et. al.in J. Fluorine Chemistry, Vol. 59, pp. 9-14 (1992).

3110Sβγ has been prepared by reaction of perfluoroethyl iodide withelemental sulfur at 300° C. under pressure as disclosed by Tiers,Journal of Organic Chemistry, Vol. 26, page 3515 (1961).

By "azeotropic" composition is meant a constant boiling liquid admixtureof two or more substances that behaves as a single substance. One way tocharacterize an azeotropic composition is that the vapor produced bypartial evaporation or distillation of the liquid has the samecomposition as the liquid from which it was evaporated or distilled,that is, the admixture distills/refluxes without compositional change.Constant boiling compositions are characterized as azeotropic becausethey exhibit either a maximum or minimum boiling point, as compared withthat of the non-azeotropic mixtures of the same components.

By "azeotrope-like" composition is meant a constant boiling, orsubstantially constant boiling, liquid admixture of two or moresubstances that behaves as a single substance. One way to characterizean azeotrope-like composition is that the vapor produced by partialevaporation or distillation of the liquid has substantially the samecomposition as the liquid from which it was evaporated or distilled,that is, the admixture distills/refluxes without substantial compositionchange. Another way to characterize an azeotrope-like composition isthat the bubble point vapor pressure and the dew point vapor pressure ofthe composition at a particular temperature are substantially the same.

It is recognized in the art that a composition is azeotrope-like if,after 50 weight percent of the composition is removed such as byevaporation or boiling off, the difference in vapor pressure between theoriginal composition and the composition remaining after 50 weightpercent of the original composition has been removed is less than 10percent, when measured in absolute units. By absolute units, it is meantmeasurements of pressure and, for example, psia, atmospheres, bars,torr, dynes per square centimeter, millimeters of mercury, inches ofwater and other equivalent terms well known in the art. If an azeotropeis present, there is no difference in vapor pressure between theoriginal composition and the composition remaining after 50 weightpercent of the original composition has been removed.

Therefore, included in this invention are compositions of effectiveamounts of HFC-338pcc and butane, cyclopropane, isobutane, propane,cyclopentane, 2,2-dimethylbutane, n-pentane, 2-methylbutane, ethylformate, propylene oxide, 3110Sβγ, cyclohexane, dimethoxyethane,2,3-dimethylpentane, 3-ethylpentane, heptane, hexane, methylcyclopentaneor THF such that after 50 weight percent of an original composition isevaporated or boiled off to produce a remaining composition, thedifference in the vapor pressure between the original composition andthe remaining composition is 10 percent or less.

For compositions that are azeotropic, there is usually some range ofcompositions around the azeotrope point that, for a maximum boilingazeotrope, have boiling points at a particular pressure higher than thepure components of the composition at that pressure and have vaporpressures at a particular temperature lower than the pure components ofthe composition at that temperature, and that, for a minimum boilingazeotrope, have boiling points at a particular pressure lower than thepure components of the composition at that pressure and have vaporpressures at a particular temperature higher than the pure components ofthe composition at that temperature. Boiling temperatures and vaporpressures above or below that of the pure components are caused byunexpected intermolecular forces between and among the molecules of thecompositions, which can be a combination of repulsive and attractiveforces such as van der Waals forces and hydrogen bonding.

The range of compositions that have a maximum or minimum boiling pointat a particular pressure, or a maximum or minimum vapor pressure at aparticular temperature, may or may not be coextensive with the range ofcompositions that have a change in vapor pressure of less than about 10%when 50 weight percent of the composition is evaporated. In those caseswhere the range of compositions that have maximum or minimum boilingtemperatures at a particular pressure, or maximum or minimum vaporpressures at a particular temperature, are broader than the range ofcompositions that have a change in vapor pressure of less than about 10%when 50 weight percent of the composition is evaporated, the unexpectedintermolecular forces are nonetheless believed important in that therefrigerant compositions having those forces that are not substantiallyconstant boiling may exhibit unexpected increases in the capacity orefficiency versus the components of the refrigerant composition.

The components of the compositions of this invention have the followingvapor pressures at 25° C.

    ______________________________________                                        COMPONENTS     PSIA           KPA                                             ______________________________________                                        HFC-337pcc     6.9            48                                              3110Sβγ                                                                           9.5            66                                              butane         35.2           243                                             cyclopropane   105.0          724                                             isobutane      50.5           348                                             propane        137.8          950                                             cyclopentane   6.1            42                                              2,2-dimethylbutane                                                                           6.2            43                                              n-pentane      10.3           71                                              2-methylbutane 13.3           92                                              ethyl formate  4.7            32                                              propylene oxide                                                                              10.4           72                                              cyclohexane    2.2            15                                              dimethoxyethane                                                                              1.7            12                                              2,3-dimethylpentane                                                                          1.3            9                                               3-ethylpentane 1.1            8                                               heptane        0.9            6                                               hexane         3.2            22                                              methylcyclopentane                                                                           2.7            18                                              THF            3.1            22                                              ______________________________________                                    

Substantially constant boiling, azeotropic or azeotrope-likecompositions of this invention comprise the following (all compositionsare measured at 25° C.):

    ______________________________________                                                         WEIGHT RANGES                                                                              PREFERRED                                       COMPONENTS       (wt. %/wt/%) (wt. %/wt. %)                                   ______________________________________                                        HFC-338pcc/butane                                                                              1-70/30-99   20-70/30-80                                     HFC-338pcc/cyclopropane                                                                        1-60/40-99   1-60/40-99                                      HFC-338pcc/isobutane                                                                           1-68/32-99   20-68/32-80                                     HFC-338pcc/propane                                                                             1-64/36-99   1-64/36-99                                      HFC-338pcc/cyclopentane                                                                        47-88/12-53  47-88/12-53                                     HFC-338pcc/2,2-dimethylbutane                                                                  46-86/14-54  46-86/14-54                                     HFC-338pcc/n-pentane                                                                           36-84/16-64  36-84/16-64                                     HFC-338pcc/2-methylbutane                                                                      33-79/21-67  33-79/21-67                                     HFC-338pcc/ethyl formate                                                                       53-99/1-47   53-99/1-47                                      HFC-338pcc/propylene oxide                                                                     1-94/6-99    40-94/6-60                                      HFC-338pcc/3110Sβγ                                                                  1-99/1-99    1-90/10-99                                      HFC-338pcc/cyclohexane                                                                         60-99/1-30   80-99/1-20                                      HFC-338pcc/dimethoxyethane                                                                     85-99/1-15   85-99/1-15                                      HFC-338pcc/2,3-dimethylpentane                                                                 62-99/1-38   62-99/1-38                                      HFC-338pcc/3-ethylpentane                                                                      63-99/1-37   63-99/1-37                                      HFC-338pcc/heptane                                                                             65-99/1-35   65-99/1-35                                      HFC-338pcc/hexane                                                                              56-93/7-44   56-93/7-44                                      HFC-338pcc/methylcyclopentane                                                                  57-99/1-43   57-99/1-43                                      HFC-338pcc/THF   78-99/1-22   78-99/1-22                                      ______________________________________                                    

For purposes of this invention, "effective amount" is defined as theamount of each component of the inventive compositions which, whencombined, results in the formation of an azeotropic or azeotrope-likecomposition. This definition includes the amounts of each component,which amounts may vary depending on the pressure applied to thecomposition so long as the azeotropic or azeotrope-like compositionscontinue to exist at the different pressures, but with possibledifferent boiling points.

Therefore, effective amount includes the amounts, such as may beexpressed in weight percentages, of each component of the compositionsof the instant invention which form azeotropic or azeotrope-likecompositions at temperatures or pressures other than as describedherein.

For the purposes of this discussion, azeotropic or constant-boiling isintended to mean also essentially azeotropic or essentially-constantboiling. In other words, included within the meaning of these terms arenot only the true azeotropes described above, but also othercompositions containing the same components in different proportions,which are true azeotropes at other temperatures and pressures, as wellas those equivalent compositions which are part of the same azeotropicsystem and are azeotrope-like in their properties. As is well recognizedin this art, there is a range of compositions which contain the samecomponents as the azeotrope, which will not only exhibit essentiallyequivalent properties for refrigeration and other applications, butwhich will also exhibit essentially equivalent properties to the trueazeotropic composition in terms of constant boiling characteristics ortendency not to segregate or fractionate on boiling.

It is possible to characterize, in effect, a constant boiling admixturewhich may appear under many guises, depending upon the conditionschosen, by any of several criteria:

The composition can be defined as an azeotrope of A, B, C (and D . . . )since the very term "azeotrope" is at once both definitive andlimitative, and requires that effective amounts of A, B, C (and D . . .) for this unique composition of matter which is a constant boilingcomposition.

It is well known by those skilled in the art, that, at differentpressures, the composition of a given azeotrope will vary at least tosome degree, and changes in pressure will also change, at least to somedegree, the boiling point temperature. Thus, an azeotrope of A, B, C(and D . . . ) represents a unique type of relationship but with avariable composition which depends on temperature and/or pressure.Therefore, compositional ranges, rather than fixed compositions, areoften used to define azeotropes.

The composition can be defined as a particular weight percentrelationship or mole percent relationship of A, B, C (and D . . . ),while recognizing that such specific values point out only oneparticular relationship and that in actuality, a series of suchrelationships, represented by A, B, C (and D . . . ) actually exist fora given azeotrope, varied by the influence of pressure.

An azeotrope of A, B, C (and D . . . ) can be characterized by definingthe compositions as an azeotrope characterized by a boiling point at agiven pressure, thus giving identifying characteristics without undulylimiting the scope of the invention by a specific numerical composition,which is limited by and is only as accurate as the analytical equipmentavailable.

The azeotrope or azeotrope-like compositions of the present inventioncan be prepared by any convenient method including mixing or combiningthe desired amounts. A preferred method is to weigh the desiredcomponent amounts and thereafter combine them in an appropriatecontainer.

Specific examples illustrating the invention are given below. Unlessotherwise stated therein, all percentages are by weight. It is to beunderstood that these examples are merely illustrative and in no way areto be interpreted as limiting the scope of the invention.

EXAMPLE 1 Phase Study

A phase study shows the following compositions are azeotropic. Thetemperature is 25° C.

    ______________________________________                                                                Vapor Press.                                          Composition      Weight Percents                                                                            psia   kPa                                      ______________________________________                                        HFC-338pcc/butane                                                                              31.0/69.0    38.3   264                                      HFC-338pcc/cyclopropane                                                                         6.5/93.5    105.5  727                                      HFC-338pcc/isobutane                                                                           22.8/77.2    53.0   365                                      HFC-338pcc/propane                                                                              3.1/96.9    137.9  951                                      HFC-338pcc/cyclopentane                                                                        72.0/28.0    11.0   75                                       HFC-338pcc/2,2-dimethylbutane                                                                  70.5/29.5    11.8   81                                       HFC-338pcc/n-pentane                                                                           63.5/36.5    13.9   96                                       HFC-338pcc/2-methylbutane                                                                      54.2/45.8    18.1   124                                      HFC-338pcc/ethyl formate                                                                       79.3/20.7    8.5    58                                       HFC-338pcc/propylene oxide                                                                     55.0/45.0    10.6   73                                       HFC-338pcc/3110Sβγ                                                                  15.7/84.3    9.7    67                                       HFC-338pcc/cyclohexane                                                                         88.6/11.4    7.91   55                                       HFC-338pcc/dimethoxyethane                                                                     96.9/3.1     7.31   50                                       HFC-338pcc/2,3-dimethylpentane                                                                 91.7/8.3     7.67   53                                       HFC-338pcc/3-ethylpentane                                                                      93.0/7.0     7.48   52                                       HFC-338pcc/heptane                                                                             94.7/5.3     7.28   50                                       HFC-338pcc/hexane                                                                              82.9/17.1    9.03   62                                       HFC-338pcc/methylcyclopentane                                                                  85.7/14.3    8.33   57                                       HFC-338pcc/THF   93.6/6.4     7.56   52                                       ______________________________________                                    

EXAMPLE 2 Impact of Vapor Leakage on Vapor Pressure at 25° C.

A vessel is charged with an initial liquid composition at 25° C. Theliquid, and the vapor above the liquid, are allowed to come toequilibrium, and the vapor pressure in the vessel is measured. Vapor isallowed to leak from the vessel, while the temperature is held constantat 25° C., until 50 weight percent of the initial charge is removed, atwhich time the vapor pressure of the composition remaining in the vesselis measured. The results are summarized below.

    ______________________________________                                                       0 wt %    50 wt %   0% change                                  Refrigerant    evaporated                                                                              evaporated                                                                              in vapor                                   Composition    psia   kPa    psia kPa  pressure                               ______________________________________                                        HFC-338pcc/butane                                                             31.0/69.0      38.3   264    38.3 264  0.0                                    15/85          38.0   262    36.8 254  3.2                                    10/90          37.7   260    35.8 247  5.1                                    5/95           37.0   255    35.3 244  4.5                                    1/99           35.7   246    35.2 243  1.4                                    50/50          38.1   263    37.9 261  0.7                                    70/30          37.5   259    34.2 236  9.0                                    71/29          37.5   258    33.6 232  10.3                                   HFC-338pcc/cyclopropane                                                       6.5/93.5       105.5  727    105.5                                                                              727  0.0                                    1/99           105.2  725    105.2                                                                              725  0.0                                    30/70          104.7  722    103.8                                                                              716  0.8                                    50/50          103.2  711    98.7 680  4.4                                    60/40          101.5  700    91.6 632  9.7                                    61/39          101.3  698    90.6 625  10.5                                   HFC-338pcc/isobutane                                                          22.8/77.2      53.0   365    53.0 365  0.0                                    10/90          52.7   363    51.8 357  1.6                                    1/99           51.0   351    50.5 348  0.8                                    60/40          52.3   361    50.4 347  3.7                                    68/32          51.8   357    46.8 323  9.7                                    69/31          51.8   357    46.0 317  11.1                                   HFC-338pcc/propane                                                            3.1/96.9       137.9  951    137.9                                                                              951  0.0                                    1/99           137.9  951    137.9                                                                              951  0.0                                    20/80          136.9  944    136.3                                                                              940  0.5                                    60/40          132.9  916    123.7                                                                              853  6.9                                    64/36          132.0  910    118.9                                                                              820  9.9                                    65/35          131.7  908    117.4                                                                              810  10.9                                   HFC-338pcc/cyclopentane                                                       72.0/28.0      11.0   75     11.0 75   0.0                                    85/15          10.8   74     10.3 71   4.8                                    88/12          10.6   73     9.6  66   9.4                                    89/11          10.6   73     9.4  64   11.5                                   50/50          10.9   75     10.7 73   1.9                                    47/53          10.9   75     10.3 71   5.4                                    46/54          10.8   75     9.7  67   10.5                                   HFC-338pcc/2,2-dimethyl-                                                      butane                                                                        70.5/29.5      11.8   81     11.8 81   0.0                                    86/14          11.7   81     10.7 73   8.8                                    87/13          11.7   80     10.2 70   12.5                                   50/50          11.8   81     11.5 79   2.1                                    46/54          11.8   81     10.8 74   8.4                                    45/55          11.8   81     10.2 71   12.9                                   HFC-338pcc/n-pentane                                                          63.5/36.5      13.9   96     13.9 96   0.0                                    80/20          13.7   94     13.2 91   3.6                                    84/16          13.6   94     12.3 85   9.6                                    85/15          13.6   94     11.8 81   13.2                                   40/60          13.6   94     12.7 88   6.6                                    36/64          13.5   93     12.2 84   9.6                                    35/65          13.5   93     12.1 83   10.4                                   HFC-338pcc/2-methylbutane                                                     54.2/45.8      18.1   124    18.1 124  0.0                                    33/67          18.0   124    16.6 114  7.9                                    32/68          18.0   124    16.0 111  10.8                                   80/20          17.8   123    15.6 107  12.5                                   79/21          17.8   123    16.0 111  10.0                                   HFC-338pcc/ethyl formate                                                      79.3/20.7      8.5    58     8.5  58   0.0                                    90/10          8.3    57     8.1  56   2.4                                    99/1           7.2    49     7.0  48   2.5                                    60/40          8.3    57     8.0  55   3.7                                    53/47          8.2    56     7.5  51   8.9                                    52/48          8.2    56     7.4  51   10.0                                   HFC-338pcc/propylene oxide                                                    55.0/45.0      10.60  73     10.60                                                                              73   0.0                                    40/60          10.57  73     10.57                                                                              73   0.0                                    20/80          10.50  72     10.50                                                                              72   0.0                                    1/99           10.43  72     10.43                                                                              72   0.0                                    80/20          10.37  71     10.29                                                                              71   0.7                                    94/6           9.59   66     8.77 60   8.6                                    95/5           9.47   65     8.25 57   12.9                                   HFC-338pcc/3110Sβγ                                                 15.7/84.3      9.7    67     9.7  67   0.0                                    1/99           9.5    66     9.5  66   0.0                                    40/60          9.4    65     9.3  64   1.1                                    60/40          8.9    62     8.6  59   3.7                                    80/20          8.1    56     7.7  53   6.0                                    90/10          7.6    52     7.2  50   5.0                                    99/1           7.0    48     6.9  48   0.7                                    HFC-338pcc/cyclohexane                                                        88.6/11.4      7.91   55     7.91 55   0.0                                    99/1           7.24   50     6.97 48   3.7                                    70/30          7.80   54     7.69 53   1.4                                    60/40          7.75   53     7.31 50   5.7                                    59/41          7.74   53     6.84 47   11.6                                   HFC-338pcc/dimethoxyethane                                                    96.9/3.1       7.31   50     7.31 50   0.0                                    99/1           7.29   50     6.88 47   5.6                                    85/15          7.01   48     6.35 44   9.4                                    84/16          6.97   48     6.21 43   10.9                                   HFC-338pcc/2,3-dimethyl-                                                      pentane                                                                       91.7/8.3       7.67   53     7.67 53   0.00                                   99/1           7.30   50     6.93 48   5.1                                    80/20          7.63   53     7.60 52   0.4                                    70/30          7.61   52     7.53 52   1.1                                    62/38          7.59   52     6.90 48   9.1                                    61/39          7.59   52     6.41 44   15.5                                   HFC-338pcc/3-ethylpentane                                                     93.0/7.0       7.48   52     7.48 52   0.0                                    99/1           7.22   50     6.94 48   3.9                                    80/20          7.44   51     7.40 51   0.5                                    70/30          7.41   51     7.32 50   1.2                                    63/37          7.40   51     6.67 46   9.9                                    62/38          7.40   51     61.3 42   17.2                                   HFC-338pcc/heptane                                                            94.7/5.3       7.28   50     7.28 50   0.0                                    99/1           7.12   49     6.97 48   2.1                                    80/20          7.22   50     7.17 49   0.7                                    70/30          7.19   50     7.07 49   1.7                                    65/35          7.18   50     6.65 46   7.4                                    64/36          7.18   50     6.32 44   12.0                                   HFC-338pcc/hexane                                                             82.9/17.1      9.03   62     9.03 62   0.0                                    93/7           8.89   61     8.10 56   8.9                                    94/6           8.83   61     7.76 54   12.1                                   60/40          8.97   62     8.76 60   2.3                                    56/44          8.96   62     8.09 56   9.7                                    55/45          8.96   62     7.51 52   16.2                                   HFC-338pcc/methylcyclo-                                                       pentane                                                                       85.7/14.3      8.33   57     8.33 57   0.0                                    95/5           8.10   56     7.59 52   6.3                                    99/1           7.34   51     6.95 48   5.3                                    57/43          8.20   57     7.57 52   7.7                                    56/44          8.19   56     6.51 45   20.5                                   HFC-338pcc/THF                                                                93.6/6.4       7.56   52     7.56 52   0.0                                    99/1           7.27   50     6.99 48   3.9                                    78/22          7.18   50     6.53 45   9.1                                    77/23          7.14   49     6.42 44   10.1                                   ______________________________________                                    

The results of this Example show that these compositions are azeotropicor azeotrope-like because when 50 wt. % of an original composition isremoved, the vapor pressure of the remaining composition is within about10% of the vapor pressure of the original composition, at a temperatureof 25° C.

EXAMPLE 3 Impact of Vapor Leakage at 0° C.

A leak test is performed on compositions of HFC-338pcc and THF, at thetemperature of 0° C. The results are summarized below.

    ______________________________________                                                  0 wt %     50 wt %                                                  Refrigerant                                                                             evaporated evaporated 0% change in                                  Composition                                                                             psia    kPa    psia  kPa  vapor pressure                            ______________________________________                                        HFC-338pcc/THF                                                                94.3/5.7  2.40    16.5   2.40  16.5 0.0                                       99/1      2.33    16.1   2.23  15.4 4.3                                       80/20     2.29    15.8   2.08  14.3 9.2                                       79/21     2.28    15.7   2.05  14.1 10.1                                      ______________________________________                                    

These results show that compositions of and are azeotropic orazeotrope-like at different temperatures, but that the weight percentsof the components vary as the temperature is changed.

EXAMPLE 4 Refrigerant Performance

The following table shows the performance of various refrigerants in anideal vapor compression cycle. The data are based on the followingconditions.

Evaporator temperature 40.0° F. (4.4° C.)

Condenser temperature 130.0° F. (54.4° C.)

Liquid subcooled 5° F. (2.8° C.)

Return Gas 60° F. (15.6° C.)

Compressor efficiency is 70%.

The refrigeration capacity is based on a compressor with a fixeddisplacement of 3.5 cubic feet per minute and 70% volumetric efficiency.Capacity is intended to mean the change in enthalpy of the refrigerantin the evaporator per pound of refrigerant circulated, i.e. the heatremoved by the refrigerant in the evaporator per time. Coefficient ofperformance (COP) is intended to mean the ratio of the capacity tocompressor work. It is a measure of refrigerant energy efficiency.

    __________________________________________________________________________                   Evap. Cond  Comp. Dis.                                                                             Capacity                                  Refrig.        Press.                                                                              Press.                                                                              Temp.    BTU/min                                   Comp.          Psia                                                                             kPa                                                                              Psia                                                                             kPa                                                                              °F.                                                                       °C.                                                                       COP                                                                              kw                                        __________________________________________________________________________    HFC-338pcc/butane                                                             1/99           17.6                                                                             121                                                                              80.4                                                                             554                                                                              161.6                                                                            72.0                                                                             2.99                                                                             76.2                                                                             1.3                                    99/1           3.2                                                                              22 22.3                                                                             154                                                                              143.9                                                                            62.2                                                                             3.00                                                                             18.0                                                                             0.3                                    HFC-338pcc/cyclopropane                                                       1/99           57.1                                                                             294                                                                              214.4                                                                            1478                                                                             211.2                                                                            99.6                                                                             3.03                                                                             226.0                                                                            4.0                                    99/1*          4.6                                                                              32 27.2                                                                             188                                                                              144.7                                                                            62.6                                                                             3.56                                                                             27.6                                                                             0.5                                    HFC-338pcc/isobutane                                                          1/99           26.1                                                                             180                                                                              109.7                                                                            756                                                                              158.0                                                                            70.0                                                                             2.87                                                                             101.6                                                                            1.8                                    99/1           3.3                                                                              23 22.6                                                                             156                                                                              143.5                                                                            61.9                                                                             3.03                                                                             18.5                                                                             0.3                                    HFC-338pcc/propane                                                            1/99           75.8                                                                             523                                                                              269.8                                                                            1860                                                                             172.1                                                                            77.8                                                                             2.63                                                                             235.2                                                                            4.1                                    99/1*          4.3                                                                              30 26.2                                                                             181                                                                              145.4                                                                            63.0                                                                             3.42                                                                             25.2                                                                             0.4                                    HFC-338pcc/cyclopentane                                                       1/99           2.6                                                                              18 17.2                                                                             119                                                                              159.3                                                                            70.7                                                                             3.16                                                                             15.2                                                                             0.3                                    99/1           3.1                                                                              21 21.3                                                                             147                                                                              143.9                                                                            62.2                                                                             2.94                                                                             16.7                                                                             0.3                                    HFC-338pcc/2,2-dimethylbutane                                                 1/99           2.7                                                                              19 16.8                                                                             116                                                                              137.7                                                                            58.7                                                                             2.94                                                                             13.9                                                                             0.2                                    99/1           3.0                                                                              21 20.9                                                                             144                                                                              143.6                                                                            62.0                                                                             2.92                                                                             16.3                                                                             0.3                                    HFC-338pcc/n-pentane                                                          1/99           4.4                                                                              30 26.6                                                                             183                                                                              155.7                                                                            68.7                                                                             3.08                                                                             23.6                                                                             0.4                                    99/1           3.2                                                                              22 22.1                                                                             152                                                                              143.3                                                                            61.8                                                                             2.99                                                                             17.8                                                                             0.3                                    HFC-338pcc/2-methylbutane                                                     1/99           6.0                                                                              41 33.2                                                                             229                                                                              148.2                                                                            64.6                                                                             3.00                                                                             29.5                                                                             0.5                                    99/1           3.0                                                                              21 21.3                                                                             147                                                                              143.9                                                                            62.2                                                                             2.93                                                                             16.7                                                                             0.3                                    HFC-338pcc/ethyl formate                                                      1/99           1.9                                                                              13 15.3                                                                             105                                                                              202.3                                                                            94.6                                                                             3.62                                                                             14.7                                                                             0.3                                    99/1           3.1                                                                              21 21.8                                                                             150                                                                              144.3                                                                            62.4                                                                             2.97                                                                             17.3                                                                             0.3                                    HFC-338pcc/propylene oxide                                                    1/99           4.5                                                                              31 28.1                                                                             194                                                                              199.0                                                                            92.8                                                                             3.31                                                                             27.5                                                                             0.5                                    99/1           3.3                                                                              23 22.3                                                                             154                                                                              144.1                                                                            62.3                                                                             3.01                                                                             18.1                                                                             0.3                                    HFC-338pcc/3110Sβγ                                                 1/99*          3.9                                                                              27 26.7                                                                             184                                                                              132.8                                                                            56.0                                                                             2.61                                                                             18.5                                                                             0.3                                    99/1           3.0                                                                              21 21.0                                                                             145                                                                              143.7                                                                            62.1                                                                             2.92                                                                             16.3                                                                             0.3                                    HFC-338pcc/cyclohexane                                                        60/40          1.5                                                                              10 12.7                                                                             88 151.2                                                                            66.2                                                                             3.19                                                                             10.1                                                                             0.2                                    99/1           3.0                                                                              21 20.8                                                                             143                                                                              213.7                                                                            100.9                                                                            3.23                                                                             14.3                                                                             0.3                                    HFC-338pcc/dimethoxyethane                                                    60/40          1.4                                                                              10 12.9                                                                             89 164.0                                                                            73.3                                                                             3.28                                                                             9.9                                                                              0.2                                    99/1           3.0                                                                              21 20.9                                                                             144                                                                              144.0                                                                            62.2                                                                             2.93                                                                             16.3                                                                             0.3                                    HFC-338pcc/2,3-dimethylpentane                                                60/40          0.7                                                                              5  7.0                                                                              48 147.2                                                                            64.0                                                                             3.21                                                                             5.2                                                                              0.1                                    99/1           2.5                                                                              17 19.0                                                                             131                                                                              147.4                                                                            64.1                                                                             2.91                                                                             14.1                                                                             0.2                                    HFC-338pcc/3-ethylpentane                                                     60/40          0.9                                                                              6  8.9                                                                              61 146.8                                                                            63.8                                                                             3.25                                                                             6.7                                                                              0.1                                    99/1           2.8                                                                              19 20.2                                                                             139                                                                              144.4                                                                            62.4                                                                             2.92                                                                             15.6                                                                             0.3                                    HFC-338pcc/heptane                                                            60/40          0.8                                                                              6  8.1                                                                              56 148.5                                                                            64.7                                                                             3.31                                                                             6.1                                                                              0.1                                    99/1           2.8                                                                              19 20.1                                                                             139                                                                              144.7                                                                            62.6                                                                             2.93                                                                             15.4                                                                             0.3                                    HFC-338pcc/hexane                                                             1/99           1.1                                                                              8  9.1                                                                              63 147.6                                                                            64.2                                                                             3.21                                                                             7.3                                                                              0.1                                    99/1           2.9                                                                              20 20.7                                                                             143                                                                              143.8                                                                            62.1                                                                             2.93                                                                             16.1                                                                             0.3                                    HFC-338pcc/methylcyclopentane                                                 1/99           1.1                                                                              8  8.4                                                                              58 151.4                                                                            66.3                                                                             3.13                                                                             6.7                                                                              0.1                                    99/1           3.0                                                                              21 20.8                                                                             143                                                                              145.7                                                                            63.2                                                                             2.95                                                                             16.3                                                                             0.3                                    HFC-338pcc/THF                                                                60/40          2.5                                                                              17 19.6                                                                             135                                                                              165.4                                                                            74.1                                                                             3.16                                                                             16.0                                                                             0.3                                    99/1           3.1                                                                              21 21.4                                                                             148                                                                              144.1                                                                            62.3                                                                             2.94                                                                             16.8                                                                             0.3                                    __________________________________________________________________________     *65° C. Return Gas                                                

EXAMPLE 5

This Example is directed to measurements of the liquid/vapor equilibriumcurves for the mixtures in FIGS. 1-6 and 8-19.

Turning to FIG. 1, the upper curve represents the composition of theliquid, and the lower curve represents the composition of the vapor.

The data for the compositions of the liquid in FIG. 1 are obtained asfollows. A stainless steel cylinder is evacuated, and a weighed amountof HFC-338pcc is added to the cylinder. The cylinder is cooled to reducethe vapor pressure of HFC-338pcc, and then a weighed amount of butane isadded to the cylinder. The cylinder is agitated to mix the HFC-338pccand butane, and then the cylinder is placed in a constant temperaturebath until the temperature comes to equilibrium at 25° C., at which timethe vapor pressure of the HFC-338pcc and butane in the cylinder ismeasured. Additional samples of liquid are measured the same way, andthe results are plotted in FIG. 1.

The curve which shows the composition of the vapor is calculated usingan ideal gas equation of state.

Vapor/liquid equilibrium data are obtained in the same way for themixtures shown in FIGS. 2-6 and 8-19.

The data in FIGS. 1-6 and 8-19 show that at 25° C., there are ranges ofcompositions that have vapor pressures higher than the vapor pressuresof the pure components of the composition at that same temperature. Asstated earlier, the higher than expected pressures of these compositionsmay result in an unexpected increase in the refrigeration capacity orefficiency for these compositions versus the pure components of thecompositions.

EXAMPLE 6

This Example is directed to measurements of the liquid/vapor equilibriumcurve for mixtures of HFC-338pcc and n-pentane. The liquid/vaporequilibrium data for these mixtures are shown in FIG. 7. The upper curverepresents the liquid composition, and the lower curve represents thevapor composition.

The procedure for measuring the composition of the liquid for mixturesof HFC-338pcc and n-pentane in FIG. 7 was as follows. A stainless steelcylinder was evacuated, and a weighed amount of HFC-338pcc was added tothe cylinder. The cylinder was cooled to reduce the vapor pressure ofHFC-338pcc, and then a weighed amount of n-pentane was added to thecylinder. The cylinder was agitated to mix the HFC-338pcc and n-pentane,and then the cylinder was placed in a constant temperature bath untilthe temperature came to equilibrium at 18.33° C., at which time thevapor pressure of the content of the cylinder was measured. Samples ofthe liquid in the cylinder were taken and analyzed, and the results areplotted in FIG. 7 as asterisks, with a best fit curve having been drawnthrough the asterisks.

This procedure was repeated for various mixtures of HFC-338pcc andn-pentane as indicated in FIG. 7.

The curve which shows the composition of the vapor is calculated usingan ideal gas equation of state.

The data in FIG. 7 show that at 18.33° C., there are ranges ofcompositions that have vapor pressures higher than the vapor pressuresof the pure components of the composition at that same temperature.

The novel compositions of this invention, including the azeotropic orazeotrope-like compositions, may be used to produce refrigeration bycondensing the compositions and thereafter evaporating the condensate inthe vicinity of a body to be cooled. The novel compositions may also beused to produce heat by condensing the refrigerant in the vicinity ofthe body to be heated and thereafter evaporating the refrigerant.

The compositions of the present inventions are useful as blowing agentsin the production of thermoset foams, which include polyurethane andphenolic foams, and thermoplastic foams, which include polystyrene orpolyolefin foams.

A polyurethane foam may be made by combining a composition of thepresent invention, which functions as a blowing agent, together with anisocyanate, a polyol, and appropriate catalysts or surfactants to form apoylurethane or polyisocyanurate reaction formulation. Water may beadded to the formulation raction to modify the foam polymer as well asto generate carbon dioxide as an in-situ blowing agent.

A phenolic foam may be produced by combining a phenolic resin or resole,acid catalysts, a blowing agent of the present invention and appropriatesurfactants to form a phenolic reaction formulation. The formulation maybe chosen such that either an open cell or closed cell phenolic foam isproduced.

Polystyrene or polyolefin foams may be made by extruing a molten mixureof a polymer, such as polystyrere, polyethylene or polypropylene), anucleating agent and a blowing agent of the present invention through anextrusion die that yields the desired foam product profile.

The novel compositions of this invention, including the azeotropic orazeotrope-like compositions, may be used as cleaning agents to clean,for example, electronic circuit boards. Electronic components aresoldered to circuit boards by coating the entire circuit side of theboard with flux and thereafter passing the flux-coated board overpreheaters and through molten solder. The flux cleans the conductivemetal parts and promotes solder fusion, but leave residues on thecircuit boards that must be removed with a cleaning agent. This isconventionally done by suspending a circuit board to be cleaned in aboiling sump which contains the azeotropic or azeotrope-likecomposition, then suspending the circuit board in a rinse sump, whichcontains the same azeotropic or azeotrope-like composition, and finally,for one minute in the solvent vapor above the boiling sump.

As a further example, the azeotropic mixtures of this invention can beused in cleaning processes such as described in U.S. Pat. No. 3,881,949,or as a buffing abrasive detergent.

It is desirable that the cleaning agents be azeotropic or azeotrope-likeso that they do not tend to fractionate upon boiling or evaporation.This behavior is desirable because if the cleaning agent were notazeotropic or azeotrope-like, the more volatile components of thecleaning agent would preferentially evaporate, and would result in acleaning agent with a changed composition that may become flammable andthat may have less-desirable solvency properties, such as lower rosinflux solvency and lower inertness toward the electrical components beingcleaned. The azeotropic character is also desirable in vapor degreasingoperations because the cleaning agent is generally redistilled andemployed for final rinse cleaning.

The novel compositions of this invention are also useful as fireextinguishing agents.

In addition to these applications, the novel constant boiling orsubstantially constant boiling compositions of the invention are alsouseful as aerosol propellants, heat transfer media, gaseous dielectrics,and power cycle working fluids.

ADDITIONAL COMPOUNDS

Other components, such as aliphatic hydrocarbons having a boiling pointof -60° to +60° C., hydrofluorocarbonalkanes having a boiling point of-60° to +60° C., hydrofluoropropanes having a boiling point of between-60° to +60° C., hydrocarbon esters having a boiling point between -60°to +60° C., hydrochlorofluorocarbons having a boiling point between -60°to +60° C., hydrofluorocarbons having a boiling point of -60° to +60°C., hydrochlorocarbons having a boiling point between -60° to +60° C.,chlorocarbons and perfluorinated compounds, can be added to theazeotropic or azeotrope-like compositions described above.

Additives such as lubricants, corrosion inhibitors, surfactants,stabilizers, dyes and other appropriate materials may be added to thenovel compositions of the invention for a variety of purposes providesthey do not have an adverse influence on the composition for itsintended application. Preferred lubricants include esters having amolecular weight greater than 250.

We claim:
 1. An azeotropic or azeotrope-like binary compositionconsisting essentially of 53-99 weight percent1,1,2,2,3,3,4,4-octafluorobutane and 1-47 weight percent ethyl formate,wherein when the temperature has been adjusted to about 25° C., thevapor pressure of the composition is higher than the vapor pressure ofthe individual components and the vapor pressure of the1,1,2,2,3,3,4,4-octafluorobutane/ethyl formate is about 7.2-8.5 psia,and the change in vapor pressure of the composition is less than about10 percent after 50 percent has been allowed to evaporate.
 2. A processfor producing refrigeration, comprising condensing a composition ofclaim 1, in the vicinity of the body to be cooled.